1. Field of the Invention
The present disclosure relates to an aircraft landing receiving apparatus and a control method thereof, and more particularly, to an aircraft landing receiving apparatus and a control method thereof capable of generating deviation information for aircraft landing by using Satellite-Based Augmentation System (SBAS) signals and Global Navigation Satellite System (GNSS) signals, and providing landing guidance information by using the same.
2. Description of the Related Art
Existing systems that provide aircrafts with landing guidance information for the safe landing of the aircraft on the runway include the Instrument Landing System (ILS), MLS, VHF Omni directional range (VOR), non-directional beacon (NDB), tactical air navigation (TACAN), GNSS, and so on. Among these, ILS and MLS provide precision approach services (CAT I/II/II), while VOR, NDB, TACAN, GNSS, and so on provide non-precision approach services.
Precision approach service refers to the service that allows an aircraft to approach at a predetermined angle of descent, by providing the aircraft with azimuth, distance and gliding angle information for the runway landing. The non-precision approach service refers to the service that is able to provide only the azimuth and distance information, but not the gliding angle (or altitude) information, thus allowing step-wise descent per flight stages. The precision approach service provides high accuracy azimuth and distance information, and thus can guide the aircraft to a point closer to the runway than the non-precision approach service is able to.
Recently, the Ground-Based Augmentation System (GBAS) and the Satellite-Based Augmentation System (SBAS) have been developed, which are the Global Navigation Satellite System (GNSS)-based systems that can provide the aircraft with landing guidance information.
Like the ILS, the GBAS can provide the precision approach service (it is currently able to provide only CAT-I service yet), while the SBAS can provide non-precision approach service. However, since the azimuth and distance information provided by the SBAS have a far greater accuracy than the existing VOR, NDB, TACAN, GNSS, and so on, it enables greater precision approach than the existing precision approach service.
Further, while the existing non-precision approach service systems are not able to provide the gliding angle information, SBAS can provide high altitude information with a certain level of accuracy (accuracy: 8-20 m), although it cannot provide the altitude information (accuracy: 4 m) comparable to that of the CAT-I precision approach service. Further, unlike the equipment mentioned above (i.e., ILS, MLS, VOR, etc., except for GNSS), SBAS provide advantage that it can receive only the SBAS augmentation information provided from the SBAS satellite and the GNSS signals provided from the GNSS satellite, and provide a certain level (e.g, APV-I, APV-II) of landing guidance services to the aircraft, without requiring separate equipment be installed on the ground.
Further, since SBAS transmits and receives signals through the satellite, unlike the other ground equipment, it can provide wide area service. Since it is possible to receive SBAS signals across the entire country through only one piece of SBAS satellite, it is not necessary to install separate ground equipment in each airport.
Meanwhile, like the existing ILS, MLS and GBAS, the SBAS can provide the azimuth and horizontal guidance information about runway, and in addition, the SBAS can also provide vertical guidance information with a certain level of accuracy. Accordingly, SBAS can generate and provide the lateral deviation and vertical deviation information provided by these systems. The currently available aircraft-mounted apparatus that can generate such deviation information includes an ILS receiver, and a multi-mode receiver (MMR). However, the ILS receiver is able to receive and process only the signals of the ILS ground equipment. The MMR is able to receive respective ILS, MLS, and GBAS signals and provide the deviation information provided by the respective systems, but it cannot generate deviation information that uses SBAS signals. The MMR has a built-in GNSS signal processing apparatus that can receive GNSS signals to generate GBAS deviation information, and the signal processing apparatus can receive the SBAS signals. However, the MMR is not configured to generate the deviation information using the SBAS signals. Further, being a high-price landing receiving apparatus, MMR is not easily used for low-price small aircrafts.
Meanwhile, ILS installed at the airport radiates directional radio waves with an analogue method. Accordingly, influence by the signal interferences due to increasing width of beams and topographic obstacles as a distance from the airport increases. Accordingly, the error in the lateral/vertical deviation information provided by the aircraft-mounted ILS receiver increases as the distance from the airport increases, and the phenomenon becomes severer particularly in the cases of small/low-price aircrafts. In contrast, the SBAS receiving signals from the satellites can provide the deviation information with a certain level of accuracy without being influenced by the distance from the runway. Particularly, at 10 NM away from the runway, in terms of accuracy aspect alone, the SBAS deviation information provides higher accuracy than the ILS deviation information.
Accordingly, increasing demand is anticipated for an aircraft landing receiving apparatus and a control method thereof, which can provide far greater approach service than the existing non-precision approach services, allow service reception at any part of the country without requiring installation of separate ground equipment at each airport, and generate deviation information for the aircraft landing and provide landing guidance information by using SBAS signals that provide accuracy exceeding a certain level.